Werner Cautreels, president and CEO of Selecta Biosciences (NASDAQ: SELB), plans to retire at the end of the year. The Watertown, MA-based drug developer says it will hire an executive search firm to find a successor. As part of the succession process, Omid Farokhzad, a member of the company’s board of directors and a co-founder of the company, has been appointed chairman of the board. Selecta expects Cautreels will remain on the board after he retires. Selecta expects to start Phase 3 studies later this year testing its lead drug, SEL-212, as a treatment for chronic severe gout.